Combinations of adapalene and benzoyl peroxide for treating acne lesions

ABSTRACT

Adapalene or a pharmaceutically acceptable salt thereof formulated into a pharmaceutical composition is useful for reducing the number of acne lesions, via daily topical application, in combination or in association with benzoyl peroxide (BPO); such treatment may be via administration of a pharmaceutical composition combining adapalene and BPO or by a concomitant application of two pharmaceutical compositions, one containing adapalene and the other containing BPO.

CROSS-REFERENCE TO EARLIER APPLICATIONS

This application is a continuation-in-part of earlier copending U.S.patent application Ser. No. 12/318,937, filed Jan. 13, 2009, which is acontinuation of PCT/EP 2007/057207, filed Jul. 12, 2007 and designatingthe United States (published in the English language on Jan. 17, 2008 asWO 2008/006888 A1), which claims benefit of U.S. Provisional ApplicationNo. 60/833,491, filed Jul. 27, 2006, and also claims priority ofApplication No. 06/52968, filed in France on Jul. 13, 2006, each earlierapplication hereby expressly incorporated by reference in its entiretyand each assigned to the assignee hereof.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to the combined or associatedadministration of adapalene and of benzoyl peroxide for reducing thenumber of acne lesions. 6-[3-(1-Adamantyl)-4-methoxyphenyl]-2-naphthoicacid (referred to hereinbelow as adapalene) is a naphthoic acidderivative with retinoid and anti-inflammatory properties. This moleculewas developed for the topical treatment of common acne and of dermatosessensitive to retinoids.

2. Description of Background and/or Related and/or Prior Art

Adapalene is marketed under the trademark Differin® at a weightconcentration of 0.1%, in the form of an “alcoholic lotion” solution, anaqueous gel and a cream. These compositions are useful for treatingacne. FR 2,837,101 describes adapalene compositions at a weightconcentration of 0.3%, for treating acne.

WO 03/0555 472 and corresponding US 2003/0170196 moreover describestable pharmaceutical compositions comprising adapalene and benzoylperoxide (BPO).

An article by Korkut and Piskin, J. Dermatology, 2005, 32: 169-173,reports the results of a study comparing a treatment combiningapplication of adapalene in the evening and application of BPO in themorning, relative to an application of each of the active principlesalone. The authors do not observe any superiority of the combinedtreatment over a period of 11 weeks of treatment.

SUMMARY OF THE INVENTION

It has now been demonstrated, surprisingly, that a therapeuticassociation or combination of adapalene and BPO can provide a degree ofsuccess in reducing the number of acne lesions and an improvement in theclinical condition of patients that are markedly superior to those of atreatment based on adapalene alone or on BPO alone, while at the sametime maintaining the same skin tolerance.

The recommended treatment may take the form of a pharmaceuticalcomposition combining adapalene and BPO, or a concomitant application oftwo pharmaceutical compositions, one comprising adapalene and the othercomprising BPO.

The present invention thus features formulation of adapalene or apharmaceutically acceptable salt thereof into a pharmaceuticalcomposition, especially at set doses, intended to be administered incombination or in association with benzoyl peroxide (BPO), for thetreatment of acne lesions, especially to reduce the number of acnelesions and to improve the clinical condition of patients.

Preferably, the acne lesions are of inflammatory and/or non-inflammatorytype.

Acne is initially characterized by keratinization disorders, which aresometimes invisible to the naked eye. Visible acne lesions then develop,while the size of the sebaceous glands and the production of sebumincrease.

The present invention specifically concerns acne lesions. The term “acnelesions” means non-inflammatory lesions (open and closed comedones) andinflammatory lesions (papules, pustules, nodules and cysts) caused byacne. Preferably, the inflammatory lesions are treated with theassociation or the combination according to the invention.

More preferably, the pharmaceutical composition is administered by dailycutaneous topical application. In other words, the invention relates tothe administration of adapalene as an agent for potentiating the actionof BPO. Reciprocally, BPO potentiates the action of adapalene.

The term “adapalene salts” means the salts formed with apharmaceutically acceptable base, especially mineral bases such assodium hydroxide, potassium hydroxide and ammonia or organic bases suchas lysine, arginine or N-methylglucamine. The term “adapalene salts”also means the salts formed with fatty amines such as dioctylamine andstearylamine.

The expression “combination of adapalene or salts thereof with benzoylperoxide” means a single composition comprising both adapalene or saltsthereof and benzoyl peroxide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 are graphs showing the change in the number of lesions overtime, upon treatment either according to the invention or not;

FIG. 4 is a graph showing the degree of success over time of treatmentaccording to the invention or not;

FIG. 5 is a bar graph evaluating the anti-inflammatory effect on earedema of treatment according to the invention or not;

FIG. 6 is a chart showing the patient disposition and baseline diseasecharacteristics for clinical trials of 3855 acne vulgaris patients;

FIG. 7A is a graph of the median percentage change from baseline intotal lesion counts for the effect of treatments, ^(†)P<0.05 vs.adapalene, BPO and vehicle for the 3855 patient clinical trials;

FIG. 7B is a graph of the median percentage change from baseline intotal lesion counts for the net effect of treatment (active minusvehicle), *adapalene and BPO acted synergistically, i.e., net effect ofadapalene-BPO greater than the sum of net effects of adapalene alone andBPO alone, for the 3855 patient clinical trials;

FIG. 7C is a chart showing the contribution of synergy to efficacy ofadapalene-BPO in the total lesion counts (synergy divided by net effectof adapalene-BPO) at selected time points over the course of the 3855patient clinical trials;

FIG. 8A is a graph of the median percentage change from baseline ininflammatory lesion counts for the effect of treatments, ^(†)P<0.05 vs.adapalene, BPO and vehicle for the 3855 patient clinical trials;

FIG. 8B is a graph of the median percentage change from baseline ininflammatory lesion counts for the net effect of treatment (active minusvehicle), *adapalene and BPO acted synergistically, i.e., net effect ofadapalene-BPO greater than the sum of net effects of adapalene alone andBPO alone, for the 3855 patient clinical trials;

FIG. 8C is a chart showing the contribution of synergy to the net effectof adapalene-BPO in inflammatory lesion counts (synergy divided by neteffect of adapalene-BPO) at selected time points over the course of the3855 patient clinical trials;

FIG. 9A is a graph of the median percentage change from baseline innon-inflammatory lesion counts for the effect of treatments, P<0.05 vs.adapalene, BPO and vehicle for the 3855 patient clinical trials;

FIG. 9B is a graph of the median percentage change from baseline innon-inflammatory lesion counts for the net effect of treatment (activeminus vehicle), *adapalene and BPO acted synergistically, i.e. neteffect of adapalene-BPO greater than the sum of net effects of adapalenealone and BPO alone, for the 3855 patient clinical trials;

FIG. 9C is a chart showing the contribution of synergy to the efficacyof adapalene-BPO in non-inflammatory lesion counts (synergy divided bynet effect of adapalene-BPO) at selected time points over the course ofthe 3855 patient clinical trials;

FIG. 10A is a graph of the success rate for the effect of treatments inthe 3855 patient clinical trials, ^(†)P<0.05 vs. adapalene, ^(§)P<0.05vs. BPO; ^(#)P<0.05 vs. vehicle;

FIG. 10B is a graph of the net effect of treatments (active minusvehicle) for the 3855 patient clinical trials, *adapalene and BPO actedsynergistically, i.e., net effect of adapalene-BPO greater than the sumof net effects of adapalene alone and BPO alone;

FIG. 10C is a chart showing the contribution of synergy to efficacy ofadapalene-BPO (synergy divided by net effect of adapalene-BPO) atselected time points over the course of the 3855 patient clinicaltrials;

FIG. 11A is a graph of local tolerability signs showing mean scores forthe severity of dryness over the course of the 3855 patient clinicaltrials;

FIG. 11B is a graph of local tolerability signs showing mean scores forthe severity of erythema over the course of the 3855 patient clinicaltrials;

FIG. 11C is a graph of local tolerability signs showing mean scores forthe severity of scaling over the course of the 3855 patient clinicaltrials;

FIG. 11D is a graph of local tolerability signs showing mean scores forthe severity of stinging/burning over the course of the 3855 patientclinical trials.

DETAILED DESCRIPTION OF BEST MODE AND SPECIFIC/PREFERRED EMBODIMENTS OFTHE INVENTION

According to one preferred embodiment, the pharmaceutical composition isa fixed combination and comprises, in a pharmaceutically acceptablemedium, (i) at least one compound selected from among adapalene andpharmaceutically acceptable salts thereof, and (ii) benzoyl peroxide(BPO). Preferably, the pharmaceutical composition is intended for asingle topical application per day.

The term “pharmaceutically acceptable medium” means a medium that iscompatible with the skin, mucous membranes and the integuments.

The term “fixed combination” should be understood as meaning acombination whose active principles are combined at fixed doses in thesame vehicle (single formula) that delivers them together to the pointof application. Preferably, the pharmaceutical composition in the formof a fixed combination is a gel; in this case, the two active principlesare dispersed and intimately mixed, during production, in the samevehicle, which delivers them together during the application of the gel.

In another embodiment of the invention, the pharmaceutical compositionis in the form of a composition A comprising adapalene, suited to beapplied concomitantly with a composition B comprising BPO. Preferably,composition A and composition B are presented in the form of a kit,preferably comprising two isolated compartments each containing one ofthe two pharmaceutical compositions A or B (dual pack) and allowingsimultaneous administration of the two compositions, or alternatively inthe form of a kit combining in the same presentation at least the twoproducts (compositions A and B) in two separate packages, preferably inthe form of tubes (co-packaging).

In this case, one skilled in this art will adapt the formula that is themost appropriate in terms of viscosity, additives, etc. to the selectedkit.

The expression “concomitant” application means that the compositions aresuited to be applied to the skin simultaneously or one after the other,in any order, or in a sequential order (for example, in which theapplication of a pharmaceutical composition B comprising BPO precedesthe application of the pharmaceutical composition A comprisingadapalene), but within a time interval of less than 1 hour, preferablyless than 30 minutes, preferably less than 15 minutes, more preferablyless than 5 minutes or even less than 1 minute.

The present invention thus also features compositions in kit formcomprising at least two components:

a first component comprising at least adapalene or a pharmaceuticallyacceptable salt thereof,

a second component comprising benzoyl peroxide,

these two components being suited to be applied concomitantly to theskin, mucous membranes and/or the integuments.

Compositions A and B are preferably useful for a single cutaneoustopical application per day.

The treatments have a variable duration, depending on the patient andthe severity of his acne. The treatment period may thus run from severalweeks to several months. A suitable treatment period is at least twoweeks, preferably from 1 to 6 months and more preferably a duration ofabout 3 months is preferable, the duration of the treatment possiblybeing prolonged, if necessary.

All the pharmaceutical compositions of the invention may comprise from0.01% to 2%, preferably from 0.05% to 0.5% and preferentially from 0.1%to 0.3% of adapalene, and from 0.1% to 20% and preferably from 0.5% to10% of BPO, more preferably from 2% to 5% of BPO and preferentially 2.5%of BPO.

All the percentages are indicated by weight relative to the total weightof the composition.

The adapalene:BPO ratio ranges from 1:1 to 1:200 and, conversely, theBPO:adapalene ratio ranges from 1:1 to 1:200. Preferably, theadapalene:BPO ratio ranges from 1:1 to 1:200 and the adapalene:BPO ratiois preferably 1:25.

Preferably, the effect of the combination of the two active principlesis at least an additive effect and preferentially a potentiation orsynergistic effect. The terms “potentiation effect” and “synergisticeffect” mean a therapeutic effect (degree of success) greater than theeffect resulting from the addition of the effects obtained by each ofthe two active principles taken separately.

When they are combined in the same pharmaceutical composition, theadapalene and the BPO are present in the pharmaceutical composition insynergistic amounts, i.e., such that a synergistic or potentiationeffect on the acne lesions and on the clinical condition of the patientis observed. Preferably, the pharmaceutical composition comprises 0.1%of adapalene and 2.5% of BPO.

When compositions A and B are administered separately, the adapalene andthe BPO are, respectively, present in composition A and composition B insynergistic amounts, i.e., such that a synergistic or potentiationeffect on the acne lesions and on the clinical condition of the patientis observed, especially when the compositions are applied in associationin equal amounts. Preferably, composition A comprises 0.1% of adapaleneand composition B comprises 2.5% of BPO.

In this regard, the examples to follow demonstrate that because of thesynergistic effect of adapalene and BPO, the invention provides greaterefficacy for the treatment of acne in general and of acne lesions inparticular and a quicker onset of action relative to monotherapies.

The pharmaceutical compositions according to the invention may be in theform of ointments, emulsions preferably in the form of creams, milks orpomades; powders, impregnated pads, solutions, gels, sprays, lotions orsuspensions. They may also be in the form of suspensions of microspheresor nanospheres or of lipid or polymer vesicles or of polymer patchesand/or of hydrogels allowing controlled release. These compositions maybe in anhydrous form, in aqueous form or in the form of an emulsion.

In one preferred embodiment of the invention, the pharmaceuticalcompositions are in the form of a gel, a cream or a solution referred toas a lotion.

Preferably, the pharmaceutical compositions combining adapalene and BPO,or the pharmaceutical compositions A and/or B, are gels.

The pharmaceutical compositions of the invention may contain inertadditives or combinations of these additives, such as:

wetting agents;

texture enhancers;

preservatives such as para-hydroxybenzoic acid esters;

stabilizers;

humidity regulators;

pH regulators;

osmotic pressure modifiers;

emulsifiers;

UV-A and UV-B screening agents; and

antioxidants, such as α-tocopherol, butylhydroxyanisole orbutylhydroxytoluene, superoxide dismutase, ubiquinol, or certainmetal-chelating agents.

Needless to say, one skilled in this art will take care to select theoptional compound(s) to be added to these compositions such that theadvantageous properties intrinsically associated with the presentinvention are not, or are not substantially, adversely affected by theenvisaged addition.

According to one particular embodiment, the pharmaceutical composition Acomprising adapalene may be an aqueous gel especially containing one ormore ingredients selected from among the carbomer 940 (BF GoodrichCarbopol 980) and propylene glycol, or a cream especially containing oneor more ingredients selected from among perhydrosqualene,cyclomethicone, PEG-20 methylglucose sesquistearate and methylglucosesesquistearate or an “alcoholic lotion” solution based on polyethyleneglycol.

Useful pharmaceutical compositions, comprising adapalene and BPO, aremoreover described in WO 03/055 472. Examples of such compositionscomprise, besides the active principles adapalene and BPO:

from 5% to 25% of water;

from 0 to 10%, preferably from 0 to 2% and preferably less than 0.5% ofliquid wetting surfactant;

from 0 to 10% of pro-penetrating agent; and

an aqueous phase comprising a pH-independent gelling agent.

According to one preferred embodiment, the preferred pharmaceuticalcomposition, comprising adapalene and BPO, is an aqueous gel having thefollowing formulation:

2.5% of BPO;

0.1% of adapalene;

0.10% of disodium EDTA;

4.00% of glycerol;

4.00% of propylene glycol;

and also, preferably:

0.05% of sodium docusate;

0.20% of poloxamer 124;

4.00% of sodium acryloyldimethyltaurate copolymer and isohexadecane andpolysorbate 80;

NaOH, in an amount sufficient to obtain a pH of 5.

The acne targeted comprises all forms of acne, including common acne,comedones, polymorphs, nodulocystic acne, acne conglobata, and secondaryacne such as solar, medicational or occupational acne. The acne may inparticular be of mild to severe intensity and preferably of mild tomoderate intensity. The compositions according to the invention may beadministered as a firstline treatment, and also after failure of otherspecific treatments including the administration of adapalene and/or ofBPO according to the conditions described by Korkut et al.

The association or combination of adapalene and of BPO makes it possibleto reduce not only the number of inflammatory acne lesions but also thenon-inflammatory acne lesions and to observe an improvement in thepatient's clinical condition. A potentiation or synergistic effect isobserved. This potentiation effect described in the example to follow isshown in the reduced number of lesions and in the percentage of curedpatients (clear) and almost cured patients (almost clear) by the size ofthe superiority of the combination at fixed doses of adapalene and ofBPO, relative to the active substances taken individually at the samedoses as the combination.

Moreover, the results of the potentiation effect of the combination ofadapalene and BPO presented in the example are statistically differentfrom the results obtained for the active substances taken individually.

The combination or association of adapalene and of BPO is thusparticularly useful for reducing the number of inflammatory and/ornon-inflammatory acne lesions. Preferably, the reduction is at leastabout 40%, preferably at least about 50% and more preferably thereduction is at least about 60%. Similarly, it is demonstrated in theexample that the reduction of the total lesions is from about 35% to 80%and preferably from about 50% to 70%.

According to another embodiment, this invention also features apharmaceutical assembly (product) comprising:

i) a container delimiting at least one compartment, the said containerbeing closed by means of a closing member; and

ii) a pharmaceutical composition comprising adapalene or apharmaceutically acceptable salt thereof and benzoyl peroxide asdescribed above, and placed inside the said compartment.

The container may be in any suitable form. It may especially be in theform of a bottle, a tube, a jar, a case, a can, a sachet or a box.

Preferably, the container comprises two compartments, and each of thesecompartments comprises either composition A or composition B.

The closing member may be in the form of a removable stopper, a lid, acover, a tear-off strip or a cap, especially of the type comprising abody fixed to the container and a cap articulated on the body. It mayalso be in the form of a member ensuring the selective closure of thecontainer, especially a pump, a valve or a clapper.

The closing member may be coupled to the container by screwing.Alternatively, the coupling from the closing member and the containermay take place other than by screwing, especially via a bayonetmechanism, by click-fastening, gripping, welding, bonding or magneticattraction. The term “click-fastening” in particular means any systeminvolving the passing of a rim or bead of material by elasticdeformation of a portion, especially of the closing member, followed byreturn to the elastically unstressed position of the said portion afterthe rim or bead has been passed.

The container may be at least partly made of thermoplastic material.Examples of thermoplastic materials include polypropylene andpolyethylene.

Alternatively, the container is made of a non-thermoplastic material,especially of glass or metal (or alloy).

The container may have rigid walls or deformable walls, especially inthe form of a tube or a tube bottle.

The container may comprise means for causing or facilitating thedistribution of the composition. By way of example, the container mayhave deformable walls so as to make the composition come out in responseto a positive pressure inside the container, this positive pressurebeing caused by elastic (or non-elastic) squeezing of the walls of thecontainer. Alternatively, especially when the product is in the form ofa stick, this stick may be driven by a piston mechanism. Still in thecase of a stick, especially of makeup product, the container maycomprise a mechanism, especially a wishbone mechanism, or a mechanismwith a threaded stem, or with a helical ramp, which is capable of movinga stick in the direction of the said opening. Such a mechanism isdescribed, for example, in FR 2,806,273 or in FR 2,775,566. Such amechanism for a liquid product is described in FR 2,727,609.

In order to further illustrate the present invention and the advantagesthereof, the following specific examples are given, it being understoodthat same are intended only as illustrative and in nowise limitative. Insaid examples to follow, all parts and percentages are given by weight,unless otherwise indicated.

EXAMPLES Example 1 Clinical Study Results

A clinical study for confirmation of efficacy was performed for atopical gel combining adapalene+benzoyl peroxide (BPO).

This gel has the following formulation (expressed as % weight/totalweight):

Adapalene 0.10% Benzoyl peroxide 2.50% Copolymer of acrylamide & sodium4.00% acryloyldimethyltaurate Sodium docusate 0.05% Disodium EDTA 0.10%Glycerol 4.00% Poloxamer 124 0.20% Propylene glycol 4.00% Purified waterqs 100% 

Protocol:

The clinical study was a multi-center, randomized, double-blind study inparallel groups, to evaluate the tolerance and the efficacy of the aboveformulation, in comparison with its own individual active substancesplaced at the same doses in gels of the same formula as that of thefixed combination (individual formulae referred to as “monads”) and incomparison with the gel vehicle (placebo formula): adapalene gel (0.1%),BPO gel (2.5%) and vehicle gel.

All the treatments were applied once a day for 12 weeks, to 517 patientssuffering from acne.

The main efficacy criteria were:

the degree of success, defined as the percentage of patients consideredas being “clear”, i.e., the patient has no more acne lesions (neithercomedones nor inflammatory lesions), reflecting an improvement in thepatient's clinical condition, or “almost clear” on the evaluation scale;

the reduction of the percentage of inflammatory and non-inflammatorylesions after 12 weeks of treatment.

Results:

The results are presented in the Table that follows.

Efficacy in week 12 ITT* Adapalene Adapalene BPO 0.1% + 0.1% 2.5%Vehicle BPO 2.5% alone alone (gel) N = 149 N = 148 N = 149 N = 71 Degreeof success (see 27.5% 15.5% 15.4% 9.9% FIG. 4) Progress of the lesions(median percentages) Number of inflammatory −62.8% −45.7% −43.6% −37.8%lesions (see FIG. 2) Number of non- −51.2% −33.3% −36.4% −37.5%inflammatory lesions (see FIG. 3) Total number of lesions −51.0% −35.4%−35.6% −31.0% (see FIG. 1) Progress of the lesions (as median absolutenumbers) Number of inflammatory −17 −13.0 −13.0 −11.0 lesions Number ofnon- −22.0 −17.0 −16.0 −14.0 inflammatory lesions Total number oflesions −40.0 −29.0 −27 −26.0 ITT* (analysis of intention to treat): allthe patients randomized in a clinical test because they come under theindication selected for the treatment to be prescribed. The missing dataare imputed by the last observation (LOCF method ** (Last ObservationCarried Forward).

1) For the 4 main criteria of the study: degree of success and progressas a percentage of the three types of lesion, the fixed combination wasfound to be statistically superior to the two monads and to the vehicle.

2) When the effect of the gel used as vehicle (V) is subtracted from theeffect of the fixed combination (C), the net clinical benefit of thefixed combination (C−V) is numerically superior to the sum of the netclinical benefits of each of the individual substances after subtractionof the vehicle effect from the adapalene (A) and BPO (B) branches,respectively, according to the equation:

(C−V)>(A−V)+(B−V).

These results systematically show a potentiation effect since the netbenefit is in favor of the gel combining adapalene+BPO, with results, interms of degree of success, that are superior to the addition ofadapalene and BPO (28% for the combination, as opposed to 16%, 15% to10% for adapalene, BPO and vehicle, respectively). In this case, theabove equation shows (28−10)>(16−10)+(15−10), i.e., 18>11, which istrue.

Similarly, the gel combining adapalene+BPO was numerically superior interms of efficacy in comparison with the individual active substancesand with the vehicle as regards the reduction in the number of all thelesions (reduction in the percentage of inflammatory andnon-inflammatory lesions).

A potentiation effect of adapalene and BPO together is thus noted, sincea 51% reduction in lesions is observed for the combination, as opposedto 35% for adapalene alone, 36% for BPO alone and 31% for the vehicle,which is expressed as a net benefit of efficacy with the above equationby (51−31)>(35−31)+(36−31), i.e., 20>9, which is true.

Example 2 Evaluation of the Anti-Inflammatory in Ear Oedema Model onBalb/c Mice

The study was carried out with 45 (5 par groups) female 9 weeks agedBalb/c ByJlc mice.

The Edema was induced by a single application of 20 μl of TPA dissolvedin acetone at 0.01%.

The treatment was administrated by single topical application of testedcompounds dissolved in TPA at 0.01% (groups 3, 4, 5, 6 and 7) anddissolved in TPA 0.01%+BPO (groups 8, 9 and 10).

The treatments activity was measured by inflammation evaluation with earthickness at T+6 hours.

The results are presented in the following table and in FIG. 5.

Repeated Repeated Annova Testing Annova Testing Ear edema Inhibition vsTPA alone vs TPA + BPO Mean sem vs TPA (%) (Dose balanced) (Dosebalanced) Acetone TPA 0.01% 26.80 3.35 TPA 0.01 + CD153 0.01% (controle)2.20 0.37 91.8 0.042 TPA 0.01% + BPO at 2.5% 22.40 2.23 16.4 TPA 0.01% +BPO at 5% 20.40 2.62 23.9 TPA 0.01% + BPO at 10% 16.20 4.03 39.6 TPA0.01% + Adapalene at 0.1% 23.40 2.01 12.7 0.0015 TPA 0.01% + Adapaleneat 0.1% + BPO at 2.5% 14.00 2.51 47.8 TPA 0.01% + Adapalene at 0.1% +BPO at 5% 10.00 2.26 62.7 TPA 0.01% + Adapalene at 0.1% + BPO at 10%11.00 3.03 59.0

Conclusion:

After a single topical application of the positive control CD0153(0.01%) diluted in TPA solution, we observed a decrease of 92% of theear thickness.

BPO at 2.5%, 5% and 10% has a slight anti-inflammatory effect, reducingthe TPA-induced ear edema respectively by 16%, 24% and 40%, with astatistically significant dose balanced effect (0.042).

Adapalene alone has a low anti-inflammatory effect, reducing theTPA-induced ear edema by 13%.

Variation of concentration of BPO was measured in combination withadapalene. Therefore, combinations of BPO at 2.5%, 5% and 10% withAdapalene at 0.1% reduce the TPA-induced ear edema respectively by 48%,63% and 59%. Combination treatment is statistically more efficient thanBPO alone (0.0015) even though the dose effect of the latest group isnon-significant regarding the TPA alone group (0.1089).

Adapalene at 0.1% increases the anti-inflammatory effect obtained withBPO whatever the tested doses.

Lower doses of BPO will be used to attempt to show a dose related effectfor the association.

These results show a potential synergistic anti-inflammatory effect ofthe combination compared to the compounds singly applied.

Further Clinical Testing

The results of several clinical trials (total of 3855 acne vulgarispatients) were analyzed to determine whether adapalene and benzoylperoxide (BPO) demonstrate a synergistic efficacy in the fixed dosecombination of 0.1% adapalene and 2.5% benzoyl peroxide.

Introduction

Combination therapy is frequently employed for management of acnevulgaris due to the multi-factorial pathogenesis of the disease.¹⁻⁴ Acnedevelopment involves multiple pathophysiologic factors, includingincrease of sebum production, ductal hypercornification, P. acnesproliferation and inflammation/immunological response.⁵ Topicalmonotherapies such as retinoids, antibiotics and benzoyl peroxide (BPO)target one or two of those factors; whereas combination therapyutilizing agents with complementary mode of action provides possibilityof targeting multiple factors simultaneously. Combination therapy withtopical retinoids and antimicrobial agents is faster and moreefficacious than antimicrobial therapy alone in reducing bothinflammatory and non-inflammatory lesions,⁶⁻⁹ and is thereforerecommended in an international consensus guideline.⁵

A fixed-dose topical combination gel containing adapalene 0.1% and BPO2.5% has recently been developed for once-daily treatment of acne. Thedistinct mechanisms of action and good efficacy/safety profiles ofadapalene and BPO make them a logical choice for combination agents.Adapalene is as efficacious as other retinoids but has a much lowerirritation potential.¹⁰ It possesses anticomedogenic, comedolytic andanti-inflammatory properties, and can be also used for long-termmaintenance.¹⁰ BPO is the most potent bactericidal agent among alltopical antibiotics,¹¹ and has the additional advantage of not beingassociated with selective pressure of bacterial resistance.¹² Inaddition, adapalene remains stable when combined with BPO even in thepresence of light.¹³ Furthermore, it has been demonstrated thatadapalene can be used in conjunction with other therapies withoutnotably increasing the incidence of skin irritation.¹⁴⁻¹⁸ Threemulticenter, double-blind, randomized and controlled studies onadapalene-BPO were conducted, and the results demonstrated a favorableefficacy/safety profile of the combination gel.¹⁹⁻²¹ Patients alsoreported to be more satisfied with the effectiveness and the overalltreatment of adapalene-BPO than with the respective monotherapies andthe gel vehicle.^(20,21)

Several combination treatments of acne utilizing antibiotics and BPO ortretinoin are currently available.²²⁻²⁴ The synergistic efficacy ofindividual components in those combinations had never been reported,although the combinations were demonstrated to be more efficacious thanthe corresponding monotherapies. In the present report, we perform apooled analysis on the data of three adapalene-BPO studies involving atotal of 3855 patients, and demonstrate a unique synergistic therapeuticactivity of adapalene and BPO when used in the fixed-dose combinationgel for treatment of acne vulgaris.

Methods and Material Study Design

Three multicenter, double-blind, randomized and controlled studies onthe efficacy and safety of adapalene-BPO were conducted in 157 centersin the U.S, Puerto Rico, Canada, Germany, Poland and Hungary.¹⁹⁻²¹Patients were randomized to receive adapalene 0.1%-BPO 2.5% (Epiduo®,Galderma Laboratories), adapalene 0.1%, BPO 2.5% or vehicle once dailyin the evening for 12 weeks. Adapalene and BPO used in the studies wereformulated in the same gel vehicle as adapalene-BPO, instead of as therespective commercial products (Differin® and Benzac®, GaldermaLaboratories). Efficacy and safety assessments were performed at eachstudy visit, occurred at baseline, weeks 1, 2, 4, 8 and 12.

These three studies were conducted in accordance with the Declaration ofHelsinki, Good Clinical Practices (GCPs) and local regulatoryrequirements. Studies were approved by institutional review boards andethics committees. All patients provided written informed consent priorto entering the studies.

Patient Selection

Eligible patients were 12 years or older with 20 to 50 inflammatorylesions (IL), 30 to 100 non-inflammatory lesions (NIL), no cysts and nomore than 1 nodule on the face. Patients enrolled in two of the threestudies (a total of 3338) had an investigator's global assessment (IGA)of 3, corresponding to “moderate” acne. Lesion counts were performed onthe face only excluding the nose. Specified washout periods wererequired for patients taking certain topical and systemic treatments.Patients were excluded if they received systemic acne treatment or haddermatological conditions requiring interfering treatments. Women wereexcluded if they were pregnant, nursing, or planning a pregnancy. Menwere excluded if they had facial hair that would interfere withassessments.

Efficacy and Safety Assessments

Efficacy assessments at each study visit included percentage change frombaseline in lesion counts (IL, NIL and total lesion) and success rate,defined as the percentage of patients who had an IGA of “clear” or“almost clear”. IGA was evaluated on a scale from 0 (clear: residualhyperpigmentation and erythema may be present) to 4 (severe: entire faceis involved, covered with comedones, numerous papules and pustules, andfew nodules and cysts).

Safety of the treatments was evaluated through reporting of adverseevents (AE) and assessments of local facial tolerability. At each studyvisit, the investigators rated signs of erythema, scaling, dryness andstinging/burning on a scale from 0 (none) to 3 (severe).

Statistical Analyses

Data from the three studies were pooled and analyzed. Efficacy wasevaluated in the intent-to-treat (ITT) population, which included allpatients who were randomized and dispensed study medicine. Safety wasassessed in the safety population, which included all patients who wererandomized and treated at least once.

Efficacy was evaluated by the Cochran-Mantel-Haenzsel (CMH) test, usinggeneral association for success rate and row mean differences byrelative to identified distribution (RIDIT) transformed scores forpercent lesion change. All tests were 2-sided.

Definition and Calculation of Synergy

Synergy was defined as the efficacy of combination (adapalene-BPO)greater than the sum of efficacy of individual components (adapalenealone and BPO alone). We took into account the vehicle effect bydeducting it from the effect of treatments:²⁵

Net effect of active agent=effect of active agent−effect of vehicleSynergy=Net effect of adapalene-BPO−(Net effect of adapalene+Net effectof BPO)>0

The degree of synergy was evaluated based on the contribution of synergyto efficacy (net effect) of adapalene-BPO:

Degree of synergy (%)=(synergy/Net effect of adapalene-BPO)×100

Results Patient Disposition and Baseline Disease Characteristics

The ITT population included a total of 3855 patients: adapalene-BPO(n=983), adapalene (n=986), BPO (n=979) and gel vehicle (n=907) (FIG.6). Patient disposition was similar among treatment groups. On average,87.2% of patients completed the studies and only 1.2% discontinued dueto “adverse event (AE)”.

Table 1 summarizes the demographic and baseline disease characteristics,which were comparable among treatment groups. Mean age of enrolledpatients was 18.3 years and the majority of patients were Caucasians(72.0%).

Table

TABLE 1 Demography and baseline disease characteristics. Adapalene BPOAdapalene-BPO Vehicle Total (N = 986) (N = 979) (N = 983) (N = 907) (N =3855) Age, year Mean 18.0 18.3 18.7 18.4 18.3 Min, max 12, 50 12, 56 12,58 12, 51 12, 58 Gender, N (%) Male 478 (48.5) 489 (49.9) 475 (48.3) 410(45.2) 1852 (48.0) Female 508 (51.5) 490 (50.1) 508 (51.7) 497 (54.8)2003 (52.0) Race, N (%) Caucasian 712 (72.2) 701 (71.6) 709 (72.1) 653(72.0) 2775 (72.0) Black 121 (12.3) 130 (13.3) 121 (12.3) 117 (12.9) 489(12.7) Asian 19 (1.9) 22 (2.2) 20 (2.0) 24 (2.6) 85 (2.2) Hispanic 115(11.7) 105 (10.7) 112 (11.4) 103 (11.4) 435 (11.3) Other 19 (1.9) 21(2.1) 21 (2.1) 10 (1.1) 71 (1.8) Median lesion counts total 77 75 76 7676 inflammatory 27 27 27 27 27 Non-inflammatory 46 45 44 46 45 GlobalSeverity, N (%) 2: Mild 28 (2.8) 15 (1.5) 25 (2.5) 13 (1.4) 81 (2.1) 3:Moderate 949 (96.2) 956 (97.7) 953 (97.0) 889 (98.3) 3747 (97.2) 4:Severe 9 (1.0) 8 (0.8) 5 (0.5) 3 (0.3) 25 (0.6)

Synergistic Efficacy of Adapalene and BPO in the Combination Gel

Adapalene-BPO was significantly more efficacious than monotherapies andvehicle in decreasing all types of lesion counts at all time points(P<0.05; FIGS. 7A, 8A and 9A). Significant difference in total,inflammatory and non-inflammatory lesion counts reduction foradapalene-BPO was observed as early as week 1 (P<0.001). After week 4,the effect of vehicle stagnated; whereas the lesion counts inadapalene-BPO group continued to decrease throughout the study periodwithout reaching a plateau. At week 12, the median percentage reductionfrom baseline in the adapalene-BPO group was 66%, 58% and 59% for IL,NIL and total lesion, respectively.

The vehicle effect was subsequently deducted and the net effect ofcombination and monotherapies were compared (FIGS. 7B, 8B and 9B).Adapalene-BPO treatment led to a faster decrease in all lesion countscompared to monotherapies during the entire study period. For totallesions, the net effect of adapalene-BPO at week 1 (7.4%) was greaterthan the sum of net effects of adapalene alone and BPO alone (1.4% plus2.4%), indicating that the two components acted synergistically in thecombination (FIG. 7B). Synergistic effect in total lesion reduction wasobserved at weeks 1, 2, 4 and 8. Similarly, it was observed from week 1until week 4 for IL reduction (FIG. 8B), and until week 8 for NILreduction (FIG. 9B).

To quantify the synergy effect, the contribution of synergy to theefficacy of adapalene-BPO was calculated. At week 1, synergy contributedto 48.7%, 62.5% and 40.9% of the efficacy of adapalene-BPO in decreasingtotal, IL and NIL counts, respectively (FIGS. 7C, 8C and 9C). The degreeof synergy was the highest at week 1 and decreased at subsequent visits.

The significant and synergistic efficacy of adapalene-BPO was alsodemonstrated in the global assessment of success rate. Results ofsuccess rate began to diverge early in favor of adapalene-BPO andcontinued throughout the study period. At week 12, adapalene-BPO (33.1%)was superior to adapalene alone (20.0%), BPO alone (23.1%) and vehicle(14.2%) (P<0.001; FIG. 10A). In addition, the combination wassignificantly better than monotherapies and vehicle at week 8 (P<0.001),and better than adapalene at all time points (P<0.05).

A synergistic efficacy of adapalene and BPO in success rate was observedat weeks 1, 4, 8 and 12 (FIG. 10B). At week 1, the net effect ofadapalene-BPO was entirely due to the synergy. At weeks 8 and 12, whenthe efficacy of adapalene-BPO was significantly superior to that ofmonotherapies, the contribution of synergy was 41.7% and 22.2%,respectively (FIG. 10C).

Safety Evaluation

The mean scores for dryness, erythema, scaling and stinging/burning inall treatment groups were lower than 1 (mild) at all study visits (FIGS.11A, 11B, 11C, 11D). The scores of adapalene-BPO at week 1 were thehighest among treatment groups; however, they decreased rapidly andbecame similar to the scores of adapalene at subsequent visits. Amajority of patients in all treatment groups experienced no or only mildirritation.

The percentage of patients who experienced treatment-related AEs washigher for adapalene-BPO (21.6%) than for other groups (15.3%, 8.5% and6.0% for adapalene, BPO and vehicle, respectively). The majority ofrelated AEs were of dermatological nature, mild to moderate in severity,occurred early in the studies and resolved without residual effects. Inadapalene-BPO group, “dry skin” occurred in 13.0% of patients andaccounted for the vast majority of related AEs.

Discussion

Although several acne combination therapies are currently available,cooperative action among the individual components of those combinationshave never been reported.²²⁻²⁴ Therefore, the synergistic efficacy ofadapalene and BPO observed in this analysis is a unique feature of thefixed-dose combination therapy. Synergy is defined as combination'seffect greater than the sum of components' effect. Since the vehicle intopical acne therapies is known to be non-negligible, the vehicle effectwas taken into account and the net effect of each treatment wascompared.

Lesion counts change from baseline provides precise information aboutefficacy of the treatment. The combination therapy is superior tomonotherapies and vehicle, leading to significantly greater reduction inall lesion counts at all time points (P<0.05). Adapalene-BPOdemonstrated an onset of action as early as week 1, possibly explainedby the highest degree of synergy observed at this time point. Such animprovement at the beginning stage of therapy may help to augmentpatient's confidence on the treatment and encourage adherence, which wasreported to be poor in general in acne treatments.²⁶ Although synergywas not observed after week 8, lesion counts continued to decrease inthe group of adapalene-BPO throughout the 12-week study period withoutstagnating, confirming the previous results of a long-term efficacystudy.¹⁶ The anti-comedogenic activity of adapalene might contribute tothe observed long-lasting efficacy of the combination, since adapalenenot only reduces the number of existing comedones, but also controls thedevelopment of microcomedoes and prevents the formation of new acnelesions.⁵

Compared to the change of lesion counts, the global assessment of IGA isperhaps clinically more relevant. The rapid reduction of lesion countsearly during the study translated into an obvious global improvement ata later stage: The success rate of adapalene-BPO was the bestnumerically from week 1, increased substantially after week 4 and becamesignificantly greater than the success rate of monotherapies and vehicleat weeks 8 and 12 (P<0.001). The synergy effect in success rate also hada longer duration than in lesion counts: At weeks 8 and 12, synergycontributed to 41.7% and 22.2% of the efficacy of adapalene-BPOrespectively, explaining the striking increase of success rate in thethird month of the study. Since lesion counts continued to decreaseafter week 12,¹⁶ it is likely that the success rate also continues toincrease after the end of the study, leading to a greater globalimprovement of acne. This long-lasting efficacy of the combination gelis crucial for treatment success of acne, due to the chronic nature ofthe disease.

Several unique features of adapalene and BPO provide potentialexplanations for the synergistic efficacy observed in the combination.First, both topical retinoids and BPO are keratolytic agents and mayaffect skin permeability by reducing the number of corneocyteslayer.²⁷⁻²⁹ Thus, the simultaneous application of adapalene and BPO mayfacilitate absorption and penetration of each other, leading to higherefficacy of both agents when used in combination.

Furthermore, adapalene has a unique anti-inflammatory activity.³⁰ Theresults of an in vitro study demonstrated that adapalene antagonizes theeffect of P. acnes on inducing the expression of toll-like receptor 2,³¹which is required by the bacteria to induce the release ofpro-inflammatory cytokine.^(32,33) In addition, adapalene can modulateimmune response by altering the expression of CD1d and IL-10,³¹ thusfurther strengthens the antimicrobial activity of the innate immunesystem.

Finally, BPO possesses weak comedolytic property, in addition to itsantimicrobial activity.⁵ P. acnes induces the release of IL-1 fromfollicular keratinocytes,^(34,35) which leads to proliferation ofkeratinocytes and contributes to the formation of comedones. Therefore,the activity of BPO against non-inflammatory lesions is most likely tobe indirect, through its bactericidal action.

Adapalene-BPO provides synergistic efficacy without causing notableincrease of irritation. The good safety profile of the combination geldemonstrated in this report is consistent with findings of previousstudies.¹⁴⁻²¹ Although the peak scores at week 1 were higher withadapalene-BPO, the overall tolerability profile of the combination wascomparable to that of adapalene monotherapy at subsequent visits. Thetemporary increase of tolerability scores can be explained by theenhanced absorption of adapalene and BPO when applied simultaneously.However, irritation was observed mostly during the first two weeks oftreatment, while the beneficial effect of synergy lasted much longer (upto 12 weeks). Furthermore, the irritation signs and dry skin conditioncan be easily managed by the concomitant usage of non-comedogenicmoisturizers, which should be recommended when physicians prescribingacne medications.

In conclusion, the fixed-dose once-daily adapalene-BPO combination gelnot only is significantly more efficacious than the correspondingmonotherapies, but also provides a unique synergistic efficacy in thetreatment of acne vulgaris.

Each patent, patent application, publication, text and literaturearticle/report cited or indicated herein is hereby expresslyincorporated by reference in its entirety.

While the invention has been described in terms of various specific andpreferred embodiments, the skilled artisan will appreciate that variousmodifications, substitutions, omissions, and changes may be made withoutdeparting from the spirit thereof. Accordingly, it is intended that thescope of the present invention be limited solely by the scope of thefollowing claims, including equivalents thereof.

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1. A regime or regimen for reducing the number of acne lesions,comprising administering to an individual afflicted therewith, a thuseffective amount of a pharmaceutical composition which comprisesadapalene or a pharmaceutically acceptable salt thereof, administered incombination or in a concomitant application with benzoyl peroxide. 2.The regime or regimen as defined by claim 1, comprising administering apharmaceutical composition which comprises fixed combination whichcomprises (i) at least one compound selected from among adapalene andpharmaceutically acceptable salts thereof, and (ii) benzoyl peroxide,formulated into a pharmaceutically acceptable medium therefor.
 3. Theregime or regimen as defined by claim 1, said acne lesions being ofinflammatory and/or non-inflammatory type.
 4. The regime or regimen asdefined by claim 3, in which the reduction of the number of inflammatoryand/or non-inflammatory acne lesions is at least about 40%.
 5. Theregime or regimen as defined by claim 2, comprising administering apharmaceutical composition in which the adapalene and the benzoylperoxide are present in synergistic amounts.
 6. The regime or regimen asdefined by claim 2, wherein the pharmaceutical composition comprises0.1% of adapalene and 2.5% of benzoyl peroxide.
 7. The regime or regimenas defined by claim 2, wherein the pharmaceutical composition is a gel.8. The regime or regimen as defined by claim 1, wherein thepharmaceutical composition is adapted for topical application.
 9. Theregime or regimen as defined by claim 1, wherein the pharmaceuticalcomposition is in the form of a composition A comprising adapalene, tobe applied concomitantly with a composition B comprising benzoylperoxide.
 10. The regime or regimen as defined by claim 9, wherein theadapalene and the benzoyl peroxide are present, respectively, incompositions A and B in synergistic amounts.
 11. The regime or regimenas defined by claim 9, wherein composition A comprises 0.1% of adapaleneand composition B comprises 2.5% of benzoyl peroxide.
 12. The regime orregimen as defined by claim 9, wherein the compositions A and B aregels.
 13. The regime or regimen as defined by claim 9, wherein thecomposition A and composition B are presented in the form of a kit. 14.The regime or regimen as defined by claim 13, wherein the kit comprisestwo isolated compartments each containing one of the two pharmaceuticalcompositions A or B.
 15. The regime or regimen as defined by claim 13,wherein the kit comprises at least one association of the twocompositions A and B, in two separate packages in the same presentation.16. The regime or regimen as defined by claim 9, wherein the saidpharmaceutical composition is composition A, to be applied in any orderor sequentially, within a time interval of less than 1 hour, withcomposition B.
 17. The regime or regimen as defined by claim 9, whereinthe compositions A and B are adapted for topical application.
 18. Theregime or regimen as defined by claim 3, wherein the pharmaceuticalcomposition is useful for reducing the number of inflammatory acnelesions.
 19. The regime or regimen as defined by claim 3, wherein thepharmaceutical composition is useful for reducing the number ofnon-inflammatory acne lesions.
 20. A method for potentiating the actionof benzoyl peroxide, comprising administering therewith adapalene or apharmaceutically acceptable salt thereof.
 21. A kit comprising at leasttwo components: a first component which comprises at least adapalene ora pharmaceutically acceptable salt thereof, and a second component whichcomprises benzoyl peroxide.
 22. A product comprising: (i) a containerdelimiting at least one compartment, the said container being sealed bymeans of a closing member; and (ii) a pharmaceutical composition whichcomprises adapalene or a pharmaceutically acceptable salt thereof andbenzoyl peroxide, confined inside the said compartment.